In many occasion you may require to check content type of a particular file. For example if a file is uploaded, it's not enough to check only file extension. For additional security you should also check the actual content type of a file so latter while processing the file no exception occurs. File could be Image, Excel, Text etc.
Let's see how this can be achieved in Java.
URL - This class represents a Uniform Resource Locator. It point to a particular resource, resource can be either a file , directory or an object. Here it refers to a file.
URLConnection - This is the super class of all classes that represent a communication link between an application and a URL.
openConnection() - This is the method of URL class which represents a connection to the remote object referred to by the URL.
getContentType() - This method of URLConnection class returns the content type of the file.